WO2021251253A1 - Fluorescent plate, wavelength conversion member, and light source device - Google Patents

Fluorescent plate, wavelength conversion member, and light source device Download PDF

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Publication number
WO2021251253A1
WO2021251253A1 PCT/JP2021/021146 JP2021021146W WO2021251253A1 WO 2021251253 A1 WO2021251253 A1 WO 2021251253A1 JP 2021021146 W JP2021021146 W JP 2021021146W WO 2021251253 A1 WO2021251253 A1 WO 2021251253A1
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WIPO (PCT)
Prior art keywords
fluorescent plate
fluorescent
void
voids
less
Prior art date
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PCT/JP2021/021146
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French (fr)
Japanese (ja)
Inventor
翔平 高久
弘樹 山内
慎二 坂
裕貴 竹内
Original Assignee
日本特殊陶業株式会社
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Application filed by 日本特殊陶業株式会社 filed Critical 日本特殊陶業株式会社
Priority to CN202180009778.7A priority Critical patent/CN115003957A/en
Priority to KR1020227019925A priority patent/KR102665902B1/en
Priority to US18/000,953 priority patent/US11754259B2/en
Priority to JP2022530514A priority patent/JP7336032B2/en
Priority to EP21822567.0A priority patent/EP4163541A4/en
Publication of WO2021251253A1 publication Critical patent/WO2021251253A1/en

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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21V—FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
    • F21V9/00—Elements for modifying spectral properties, polarisation or intensity of the light emitted, e.g. filters
    • F21V9/30—Elements containing photoluminescent material distinct from or spaced from the light source
    • F21V9/32—Elements containing photoluminescent material distinct from or spaced from the light source characterised by the arrangement of the photoluminescent material
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21V—FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
    • F21V13/00—Producing particular characteristics or distribution of the light emitted by means of a combination of elements specified in two or more of main groups F21V1/00 - F21V11/00
    • F21V13/02—Combinations of only two kinds of elements
    • F21V13/08—Combinations of only two kinds of elements the elements being filters or photoluminescent elements and reflectors
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21S—NON-PORTABLE LIGHTING DEVICES; SYSTEMS THEREOF; VEHICLE LIGHTING DEVICES SPECIALLY ADAPTED FOR VEHICLE EXTERIORS
    • F21S2/00—Systems of lighting devices, not provided for in main groups F21S4/00 - F21S10/00 or F21S19/00, e.g. of modular construction
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21V—FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
    • F21V29/00—Protecting lighting devices from thermal damage; Cooling or heating arrangements specially adapted for lighting devices or systems
    • F21V29/50—Cooling arrangements
    • F21V29/502—Cooling arrangements characterised by the adaptation for cooling of specific components
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21V—FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
    • F21V29/00—Protecting lighting devices from thermal damage; Cooling or heating arrangements specially adapted for lighting devices or systems
    • F21V29/50—Cooling arrangements
    • F21V29/70—Cooling arrangements characterised by passive heat-dissipating elements, e.g. heat-sinks
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21V—FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
    • F21V29/00—Protecting lighting devices from thermal damage; Cooling or heating arrangements specially adapted for lighting devices or systems
    • F21V29/50—Cooling arrangements
    • F21V29/70—Cooling arrangements characterised by passive heat-dissipating elements, e.g. heat-sinks
    • F21V29/83—Cooling arrangements characterised by passive heat-dissipating elements, e.g. heat-sinks the elements having apertures, ducts or channels, e.g. heat radiation holes
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21V—FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
    • F21V3/00—Globes; Bowls; Cover glasses
    • F21V3/04—Globes; Bowls; Cover glasses characterised by materials, surface treatments or coatings
    • F21V3/06—Globes; Bowls; Cover glasses characterised by materials, surface treatments or coatings characterised by the material
    • F21V3/08—Globes; Bowls; Cover glasses characterised by materials, surface treatments or coatings characterised by the material the material comprising photoluminescent substances
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21V—FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
    • F21V7/00—Reflectors for light sources
    • F21V7/04—Optical design
    • F21V7/05—Optical design plane
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21V—FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
    • F21V7/00—Reflectors for light sources
    • F21V7/22—Reflectors for light sources characterised by materials, surface treatments or coatings, e.g. dichroic reflectors
    • F21V7/24—Reflectors for light sources characterised by materials, surface treatments or coatings, e.g. dichroic reflectors characterised by the material
    • F21V7/26—Reflectors for light sources characterised by materials, surface treatments or coatings, e.g. dichroic reflectors characterised by the material the material comprising photoluminescent substances
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21V—FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
    • F21V9/00—Elements for modifying spectral properties, polarisation or intensity of the light emitted, e.g. filters
    • F21V9/40—Elements for modifying spectral properties, polarisation or intensity of the light emitted, e.g. filters with provision for controlling spectral properties, e.g. colour, or intensity
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21Y—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES F21K, F21L, F21S and F21V, RELATING TO THE FORM OR THE KIND OF THE LIGHT SOURCES OR OF THE COLOUR OF THE LIGHT EMITTED
    • F21Y2115/00—Light-generating elements of semiconductor light sources
    • F21Y2115/10—Light-emitting diodes [LED]
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21Y—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES F21K, F21L, F21S and F21V, RELATING TO THE FORM OR THE KIND OF THE LIGHT SOURCES OR OF THE COLOUR OF THE LIGHT EMITTED
    • F21Y2115/00—Light-generating elements of semiconductor light sources
    • F21Y2115/30—Semiconductor lasers
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E10/00—Energy generation through renewable energy sources
    • Y02E10/50—Photovoltaic [PV] energy
    • Y02E10/52—PV systems with concentrators

Definitions

  • the present invention relates to a fluorescent screen, a wavelength conversion member, and a light source device.
  • Patent Document 1 discloses a technique for forming a void in which light is reflected by a fluorescent phase inside a fluorescent plate.
  • the fluorescent plate described in Patent Document 1 includes a plurality of voids having a relatively wide inner diameter distribution, from voids smaller than 3 ⁇ m to voids larger than 12 ⁇ m. If the inner diameter of the voids varies in this way, the scattering direction of the light scattered in the voids also varies widely, which may reduce the light extraction efficiency of the fluorescent screen.
  • An object of the present invention is to provide a technique for improving the light extraction efficiency in a fluorescent screen.
  • the present invention has been made to solve at least a part of the above-mentioned problems, and can be realized as the following forms.
  • a fluorescent plate includes a fluorescent phase that emits fluorescence by excitation light and a plurality of voids, and corresponds to a circle of voids having a circle equivalent diameter of 0.4 ⁇ m or more and 50 ⁇ m or less in the cross section of the fluorescent plate including the cross section of the voids.
  • the standard deviation of the diameter is 1.5 or less.
  • the standard deviation of the circle equivalent diameter of the void having a circle equivalent diameter of 0.4 ⁇ m or more and 50 ⁇ m or less is 1.5 or less. ing. That is, in the voids having a circle-equivalent diameter of 0.4 ⁇ m or more and 50 ⁇ m or less in the fluorescent plate, the variation in the circle-equivalent diameter is relatively small, and the fluorescent plate has voids of the same size. As a result, the variation in the reflection of light in the fluorescent phase in the void becomes small, so that the reflectance due to the void can be increased as compared with the case where the diameter corresponding to the circle of the void has a large variation. Therefore, in the fluorescent plate, the light extraction efficiency can be improved.
  • the ratio of the number of voids having a circle equivalent diameter of 1 ⁇ m or more and less than 10 ⁇ m may be 90% or more among the voids having a circle equivalent diameter of 0.4 ⁇ m or more and 50 ⁇ m or less. ..
  • the voids having a circle-equivalent diameter of 1 ⁇ m or more and less than 10 ⁇ m are 90% or more in proportion to the number of the voids in the fluorescent plate.
  • the ratio of the area occupied by the void having the equivalent circle diameter of 0.4 ⁇ m or more and 50 ⁇ m or less in the cross section of the fluorescent plate including the cross section of the void is 3% or more and 15% or less. May be good.
  • the area ratio of the area in the cross section of the fluorescent plate is 3% or more and 15% or less in the voids having the equivalent circle diameter of 0.4 ⁇ m or more and 50 ⁇ m or less.
  • the ratio of the area in the cross section of the fluorescent plate is large, the distance between the adjacent voids becomes short, so that the reflection is repeated and the light is easily attenuated.
  • the fluorescent plate of the above-mentioned form it is possible to improve the efficiency of extracting light to the outside of the fluorescent plate by suppressing the occurrence of these adverse effects.
  • the fluorescent plate of the above embodiment further includes a translucent phase that transmits the excitation light, and is the sum of the fluorescent phase and the translucent phase that occupy the fluorescent plate in the cross section of the fluorescent plate including the cross section of the void.
  • the area ratio of the fluorescent phase to the light of the fluorescent phase may be 95% or less.
  • the voids are less likely to have a distorted shape, so that deterioration of the standard deviation of the equivalent circle diameter can be suppressed. Therefore, it is possible to suppress a decrease in the efficiency of extracting light to the outside of the fluorescent screen.
  • a wavelength conversion member includes the above-mentioned fluorescent plate and a reflective member arranged on the fluorescent plate and reflecting the excitation light and the fluorescence.
  • the wavelength conversion member includes a reflection member that reflects the fluorescence emitted from the fluorescent plate and the excitation light.
  • the wavelength conversion member of the above-described embodiment may further include a heat-dissipating member that releases the heat of the fluorescent plate to the outside.
  • the wavelength conversion member includes a heat radiating member that releases the heat of the fluorescent plate to the outside.
  • a light source device may include the above-mentioned wavelength conversion member and a light source for irradiating the fluorescent plate with the excitation light.
  • the light source device includes a light source that irradiates the fluorescent plate with excitation light.
  • the fluorescent plate emits fluorescence by the excitation light. Since the emitted light including fluorescence is reflected by the fluorescent phase exposed in a relatively large amount in the void, the amount of light emitted to the outside of the fluorescent plate increases. Thereby, the light emission intensity of the light source device can be improved.
  • the present invention can be realized in various aspects, for example, a method for manufacturing a fluorescent screen, a method for manufacturing a wavelength conversion member, a method for manufacturing a light source device, a system including a light source device, a method for controlling a light source device, and the like. It can be realized in the form of a computer program or the like for causing the manufacturing device to manufacture the light source device.
  • FIG. 1 It is a schematic diagram of the light source apparatus provided with the fluorescent plate of 1st Embodiment. It is an enlarged sectional view of a fluorescent plate. It is a figure which shows the 1st result of the evaluation test of the fluorescent plate of 1st Embodiment. It is a figure which shows the 2nd result of the evaluation test of the fluorescent plate of 1st Embodiment. It is a figure which shows the 3rd result of the evaluation test of the fluorescent plate of 1st Embodiment.
  • FIG. 1 is a schematic view of a light source device 3 including the fluorescent screen 1 of the first embodiment.
  • the fluorescent plate 1 of the present embodiment is different from the light L1 when it is irradiated with the light L1 emitted by the light source 9 such as a light emitting diode (LED: Light Emitting Diode) or a semiconductor laser (LD: Laser Diode) included in the light source device 3. It emits light of a wavelength as fluorescence.
  • the fluorescence emitted by the fluorescence plate 1 is radiated in a predetermined direction as light L2 together with the light that did not contribute to the generation of fluorescence in the fluorescence plate 1. As shown in FIG.
  • the light source device 3 of the present embodiment is a reflection type light source device and is used in various optical devices such as head lamps, lighting, and projectors.
  • the light source device 3 includes the above-mentioned light source 9 and a wavelength conversion member 2.
  • the wavelength conversion member 2 includes a fluorescent plate 1, a reflection member 6, a heat dissipation member 7, and a bonding layer 8. For convenience of explanation, the relationship between the sizes of the members in FIG. 1 is shown so as to be different from the actual relationship.
  • the fluorescent plate 1 is a flat plate member formed of a ceramic sintered body.
  • the fluorescent plate 1 is formed with an incident surface 1a on which the light L1 is incident and a back surface 1b located on the opposite side of the incident surface 1a.
  • the fluorescent plate 1 emits fluorescence by using the light L1 incident from the incident surface 1a as excitation light.
  • the fluorescent plate 1 generates heat when it emits fluorescence.
  • the detailed configuration of the fluorescent plate 1 will be described later.
  • the reflective member 6 is a thin film containing silver (Ag) as a main component, and is formed on the back surface 1b of the fluorescent plate 1.
  • the reflecting member 6 reflects the light transmitted through the fluorescent screen 1 among the light L1 emitted by the light source 9 and the fluorescence toward the back surface 1b of the fluorescence emitted by the fluorescent plate 1 in the direction of the incident surface 1a.
  • the reflective member 6 may be made of a material having a high reflectance such as a silver alloy or aluminum (Al).
  • the heat radiating member 7 is a flat plate member made of a material having higher thermal conductivity than the fluorescent plate 1, such as copper, copper molybdenum alloy, copper tungsten alloy, aluminum, and aluminum nitride.
  • the heat radiating member 7 radiates the heat of the fluorescent plate 1 transmitted through the bonding layer 8 to the outside.
  • the heat radiating member 7 may be a single-layered member made of the above-mentioned material, or may be a multi-layered member made of the same or different materials. Further, a metal film that enhances the adhesion to the bonding layer 8 may be arranged on the surface 7a of the heat radiating member 7 on the fluorescent plate 1 side.
  • the bonding layer 8 is arranged between the reflecting member 6 and the heat radiating member 7, and is formed of gold (Au) and tin (Sn).
  • the bonding layer 8 joins the fluorescent plate 1 and the heat radiating member 7, and transfers the heat generated by the fluorescent plate 1 to the heat radiating member 7.
  • the bonding layer 8 may be solder formed from other materials in addition to being formed from gold and tin, or may be obtained by sintering fine powder such as silver or copper (Cu). May be good.
  • FIG. 2 is an enlarged cross-sectional view of the fluorescent plate 1.
  • the fluorescent plate 1 has a fluorescent phase 10, a translucent phase 20, and a void 30.
  • the fluorescent phase 10 is composed of a plurality of fluorescent crystal particles.
  • the fluorescent crystal particles have a composition represented by the chemical formula A 3 B 5 O 12 : Ce (so-called garnet structure).
  • a 3 B 5 O 12 : Ce means that Ce is dissolved in A 3 B 5 O 12 and a part of the element A is replaced with Ce.
  • Chemical formula A 3 B 5 O 12 : Element A and element B in Ce are each composed of at least one element selected from the following element groups.
  • Element A Lanthanoids excluding Sc, Y, Ce (however, Gd may be further contained as element A).
  • Element B Al (However, Ga may be further contained as element B)
  • the composition and element types of the fluorescent crystal particles constituting the fluorescent phase 10 are not limited to the above-mentioned composition and element types, and one fluorescent phase 10 is composed of a plurality of types of fluorescent crystal particles. May be good.
  • the translucent phase 20 is composed of a plurality of translucent crystal particles.
  • the translucent crystal particles have a composition represented by the chemical formula Al 2 O 3.
  • the translucent phase 20 transmits light inside the fluorescent plate 1 and also serves as a heat transfer path for efficiently transmitting the heat generated when the fluorescent phase 10 emits fluorescence to the heat radiating member 7.
  • the refractive index of the translucent phase 20 is smaller than that of the fluorescent phase 10.
  • the void 30 is formed by being surrounded by the fluorescent phase 10 and the translucent phase 20.
  • the fluorescent plate 1 includes a plurality of voids 30.
  • the standard deviation of the equivalent circle diameter of the void 30 having the equivalent circle diameter of 0.4 ⁇ m or more and 50 ⁇ m or less is 1.5 or less.
  • the ratio of the number of voids 30 having a circle equivalent diameter of 1 ⁇ m or more and less than 10 ⁇ m is 90% or more.
  • the plurality of voids 30 included in the fluorescent plate 1 have a small variation in the diameter corresponding to the circle. This is due to the fact that the particle size of the pore-forming material as a raw material is uniform and that the pore-forming material is sufficiently dispersed in the raw material in the method for producing the fluorescent plate 1 described later.
  • the average circle-equivalent diameter of the void 30 is between 1 ⁇ m and 10 ⁇ m, and when the average circle-equivalent diameter is in this range, it is more necessary to increase the reflectance of visible light by the void. preferable.
  • the refractive index of the void 30 is smaller than that of the translucent phase 20. That is, the refractive index of the void 30 is smaller than the refractive index of the fluorescent phase 10.
  • the ratio of the area occupied by the void 30 having the equivalent circle diameter of 0.4 ⁇ m or more and 50 ⁇ m or less is 3% or more and 15 It is less than%.
  • the voids 30 having a circle equivalent diameter of 0.4 ⁇ m or more and 50 ⁇ m or less exist inside the fluorescent plate 1 at a volume ratio of 3% or more and 15% or less.
  • the area ratio of the fluorescent phase 10 to the total of the fluorescent phase 10 and the translucent phase 20 in the fluorescent plate 1 is 60%.
  • the portion of the fluorescent plate 1 excluding the void 30 is composed of a fluorescent phase 10 having a volume ratio of 60% and a translucent phase 20 having a volume ratio of 40%.
  • the area ratio of the fluorescent phase 10 is preferably 95% or less so that sintering can easily proceed and voids are less likely to be formed.
  • the method for producing the fluorescent plate 1 first, weighed Al 2 O 3 , Y 2 O 3 , and CeO 2 were put into a ball mill together with pure water, and pulverized and mixed for 16 hours. The slurry obtained by this pulverization and mixing was dried, and the dried slurry was used for granulation with a spray dryer. Next, a predetermined amount of pore-forming material and a predetermined amount of binder are mixed with the granulated particles, and kneading is performed using a screw-type kneader while applying a high shearing force to prepare clay. did.
  • the fluorescent plate 1 is manufactured by molding the produced clay into a sheet shape using an extrusion molding machine, firing at 1700 ° C. in an air atmosphere, and sintering the soil.
  • the wavelength conversion member 2 including the fluorescent plate 1 when the wavelength conversion member 2 including the fluorescent plate 1 is manufactured, silver is vapor-deposited or sputtered on the back surface 1b of the fluorescent plate 1 to form a film of the reflective member 6.
  • the gold-tin solder foil is sandwiched between the reflective member 6 and the heat-dissipating member 7 formed on the fluorescent plate 1 and heated in a reflow oven in a nitrogen atmosphere or a hydrogen atmosphere.
  • the fluorescent plate 1 and the heat radiating member 7 are joined to each other, and the wavelength conversion member 2 is manufactured.
  • the gold-tin solder paste may be applied to bond the fluorescent plate 1 and the heat radiating member 7.
  • the light source 9 is set so that the incident surface 1a of the fluorescent plate 1 included in the wavelength conversion member 2 is irradiated with light, and the wavelength conversion member 2 and the light source 9 are provided. And package. As a result, the light source device 3 is manufactured.
  • the characteristics of the sample were measured using the following method. -A sample with a diameter equivalent to a circle of voids was cut, and the mirror-finished cut surface was observed by FE-SEM. In the image analysis using WinROOF, cross-sectional images were acquired at arbitrary five points and used in the intercept method to measure the equivalent circle diameter of the void. Dispersibility Using the intercept method described above, the distribution of the measured circle-equivalent diameter of the void (vertical axis: frequency, horizontal axis: circle-equivalent diameter) was calculated. At this time, the difference between the circle-equivalent diameters indicating the maximum frequency and the circle-equivalent diameter at which the frequency is 5% of the total was calculated and used as the dispersibility.
  • -Standard deviation The standard deviation was calculated from the equivalent circle diameter of the voids measured using the intercept method described above.
  • -Area ratio of voids In the cross-sectional image of the sample binarized by image processing, the total area of multiple voids and the area of the part other than the voids are calculated, and the total area of the plurality of voids with respect to the total area of the cross-sectional image. The ratio of was calculated.
  • -A sample for luminance measurement was prepared by polishing so that the thickness of the luminance sample was 200 ⁇ m and mirror-finishing the surface. This luminance measurement sample was irradiated with a laser having a wavelength of 450 nm (laser diameter: 0.4 mm, laser output: 5 W), and the light in the reflection direction was measured with a luminance meter.
  • FIG. 3 is a diagram showing the first result of the evaluation test of the fluorescent plate 1 of the first embodiment.
  • FIG. 4 is a diagram showing the second result of the evaluation test of the fluorescent plate 1 of the first embodiment.
  • FIG. 5 is a diagram showing the third result of the evaluation test of the fluorescent plate 1 of the first embodiment.
  • the ratio of the fluorescent phase in one sample is 60% by volume in the method according to the method for manufacturing the fluorescent plate 1 described above. , Al 2 O 3 , Y 2 O 3 , and CeO 2, and sample 1, sample 2, and sample by changing the particle size distribution of the pore-forming material to be mixed with the granulated particles. 4 particles were prepared. Further, in the sample 3, the clay was prepared without adding the pore-forming material.
  • FIG. 3 shows the test results for the standard deviation of the equivalent circle diameter of the void.
  • the sample 1 shown in the table of FIG. 3 is a sample simulating the fluorescent screen 1 of the present embodiment, and is used as a reference sample in this evaluation test. As shown in FIG.
  • the equivalent circle diameter of the void is larger than 1.0 ⁇ m and smaller than 10 ⁇ m (3.5 ⁇ m, 4.2 ⁇ m, 5, 4 ⁇ m), the brightness is 600 cd / mm 2 or more, which may be a relatively high value. It became clear.
  • FIG. 5 shows the test results regarding the area ratio of the voids in the cross section of the fluorescent screen.
  • Sample 1 shown in the table of FIG. 5 is a reference sample also shown in FIG.
  • the brightness is a relatively low value (1%: 330cd / mm 2 , 30%: 280cd / mm 2 ). It became clear that it would be.
  • the area ratio of the voids was 3% or more and 15% or less (3%, 8%, 15%), the brightness was 670 cd / mm 2 or more, which was a relatively high value.
  • the void 30 included in the fluorescent plate 1 is a circle of voids 30 having a circle equivalent diameter of 0.4 ⁇ m or more and 50 ⁇ m or less in the cross section of the fluorescent plate 1 including the cross section of the void 30.
  • the standard deviation of the equivalent diameter is 1.5 or less. That is, the void 30 having the equivalent circle diameter of 0.4 ⁇ m or more and 50 ⁇ m or less in the fluorescent plate 1 has a relatively small variation in the equivalent circle diameter, and the fluorescent plate 1 has the void 30 having the same size. It becomes.
  • the variation in the reflection of light in the fluorescent phase 10 in the void 30 becomes small, so that the reflectance due to the void 30 can be increased as compared with the case where the diameter corresponding to the circle of the void 30 has a large variation. Therefore, in the fluorescent plate 1, the light extraction efficiency can be improved.
  • the voids 30 having a circular equivalent diameter of 0.4 ⁇ m or more and 50 ⁇ m or less are the ratio of the number. It is 90% or more.
  • the variation in the reflection of light in the fluorescent phase 10 in the void 30 is further reduced, so that the reflectance due to the void 30 can be further increased. Therefore, in the fluorescent plate 1, the light extraction efficiency can be further improved.
  • the air gap 30 having a circle equivalent diameter of 0.4 ⁇ m or more and 50 ⁇ m or less has an area ratio of 3% or more and 15% or less in the cross section of the fluorescent plate 1.
  • the ratio of the area in the cross section of the fluorescent plate is small, the number of reflections is small and the reflectance is lowered.
  • the ratio of the area in the cross section of the fluorescent plate is large, the distance between the adjacent voids becomes short, so that the reflection is repeated and the light is easily attenuated.
  • the efficiency of extracting light to the outside of the fluorescent plate 1 can be improved by suppressing the occurrence of these adverse effects.
  • the fluorescent plate 1 of the present embodiment in the cross section of the fluorescent plate 1 including the cross section of the void 30, the area ratio of the fluorescent phase 10 to the total of the fluorescent phase 10 and the translucent phase 20 in the fluorescent plate 1 is 60%. ing.
  • sintering is facilitated and voids are less likely to be formed, so that the voids are less likely to have a distorted shape, and deterioration of the standard deviation of the equivalent circle diameter can be suppressed. Therefore, it is possible to suppress a decrease in the efficiency of extracting light to the outside of the fluorescent plate 1.
  • the wavelength conversion member 2 includes a reflection member 6 that reflects the fluorescence emitted from the fluorescent plate 1 and the excitation light.
  • a reflection member 6 that reflects the fluorescence emitted from the fluorescent plate 1 and the excitation light.
  • the wavelength conversion member 2 includes a heat dissipation member 7 that releases the heat of the fluorescent plate 1 to the outside.
  • a heat dissipation member 7 that releases the heat of the fluorescent plate 1 to the outside.
  • the light source device 3 includes a light source 9 that irradiates the fluorescent plate 1 with the light L1.
  • the fluorescent plate 1 emits fluorescence by a part of the light of the light L1. Since the fluorescence emitted by the fluorescent plate 1 is reflected by the fluorescent phase 10 exposed in a relatively large amount in the void 30, the amount of light radiated to the outside of the fluorescent plate 1 increases. Thereby, the light emission intensity of the light source device 3 can be improved.
  • the ratio of the area occupied by the void 30 having the equivalent circle diameter of 0.4 ⁇ m or more and 50 ⁇ m or less is 3% or more and 15% or less.
  • the ratio of the area occupied by the void 30 having the equivalent circle diameter of 0.4 ⁇ m or more and 50 ⁇ m or less is not limited to this. It may be smaller than 3% or larger than 15%, but if there are too few voids, the effect of reflection in the voids will be small, and if there are too many voids, the number of reflections will increase and the light will be attenuated and the reflectance will decrease. Therefore, 3% or more and 15% or less are desirable.
  • the area ratio of the fluorescent phase 10 is 10% or more and 95% or less so that unintended voids are not formed as much as possible when the fluorescent plate 1 is sintered.
  • the light source device 3 is a reflection type light source device.
  • the fluorescent plate 1 may be applied to a transmission type light source device.

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  • General Engineering & Computer Science (AREA)
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Abstract

This fluorescent plate comprises a fluorescent phase that fluoresces due to excitation light and a plurality of voids. In a cross section of the fluorescent plate that includes cross sections of the voids, the standard deviation of the equivalent circle diameter of voids having an equivalent circle diameter of 0.4-50 μm inclusive is less than or equal to 1.5.

Description

蛍光板、波長変換部材、および、光源装置Fluorescent plate, wavelength conversion member, and light source device
　本発明は、蛍光板、波長変換部材、および、光源装置に関する。 The present invention relates to a fluorescent screen, a wavelength conversion member, and a light source device.
　従来から、光を照射すると蛍光を発する蛍光板が知られている。近年の蛍光板は、光が照射されると照射された光の波長とは異なる波長の光を発する蛍光相を備えるなど、高機能化させているものが多く知られている。例えば、特許文献１には、蛍光板の内部において、蛍光相で光を反射させる空隙を形成する技術が開示されている。 Conventionally, a fluorescent plate that emits fluorescence when irradiated with light has been known. In recent years, many fluorescent plates are known to have high functionality, such as having a fluorescent phase that emits light having a wavelength different from the wavelength of the irradiated light when irradiated with light. For example, Patent Document 1 discloses a technique for forming a void in which light is reflected by a fluorescent phase inside a fluorescent plate.
特許５９８９２６８号公報Japanese Patent No. 5989268
　しかしながら、上記先行技術によっても、蛍光板において、光の取り出し効率を向上するためには、なお、改善の余地があった。例えば、特許文献１に記載の蛍光板は、３μｍより小さい空隙から１２μｍより大きい空隙まで、内径の分布が比較的広い複数の空隙を備えている。このように空隙の内径にばらつきがあると、空隙において散乱される光の散乱方向もばらつきが大きくなるため、蛍光板における光の取り出し効率が低下するおそれがあった。 However, even with the above-mentioned prior art, there is still room for improvement in order to improve the light extraction efficiency of the fluorescent screen. For example, the fluorescent plate described in Patent Document 1 includes a plurality of voids having a relatively wide inner diameter distribution, from voids smaller than 3 μm to voids larger than 12 μm. If the inner diameter of the voids varies in this way, the scattering direction of the light scattered in the voids also varies widely, which may reduce the light extraction efficiency of the fluorescent screen.
　本発明は、蛍光板において、光の取り出し効率を向上する技術を提供することを目的とする。 An object of the present invention is to provide a technique for improving the light extraction efficiency in a fluorescent screen.
　本発明は、上述の課題の少なくとも一部を解決するためになされたものであり、以下の形態として実現することが可能である。 The present invention has been made to solve at least a part of the above-mentioned problems, and can be realized as the following forms.
　（１）本発明の一形態によれば、蛍光板が提供される。この蛍光板は、励起光によって蛍光を発する蛍光相と、複数の空隙と、を備え、前記空隙の断面を含む前記蛍光板の断面において、円相当径が０．４μｍ以上５０μｍ以下となる空隙の円相当径の標準偏差は、１．５以下である。 (1) According to one embodiment of the present invention, a fluorescent plate is provided. This fluorescent plate includes a fluorescent phase that emits fluorescence by excitation light and a plurality of voids, and corresponds to a circle of voids having a circle equivalent diameter of 0.4 μm or more and 50 μm or less in the cross section of the fluorescent plate including the cross section of the voids. The standard deviation of the diameter is 1.5 or less.
　この構成によれば、蛍光板が備える空隙は、空隙の断面を含む蛍光板の断面において、円相当径が０．４μｍ以上５０μｍ以下となる空隙の円相当径の標準偏差が、１．５以下となっている。すなわち、蛍光板において円相当径が０．４μｍ以上５０μｍ以下となる空隙は、円相当径のばらつきが比較的小さくなっており、蛍光板には、同じような大きさの空隙があることとなる。これにより、空隙における蛍光相での光の反射のばらつきが小さくなるため、空隙の円相当径に大きなばらつきがある場合に比べ、空隙による反射率を高めることができる。したがって、蛍光板において、光の取り出し効率を向上することができる。 According to this configuration, in the cross section of the fluorescent plate including the cross section of the void, the standard deviation of the circle equivalent diameter of the void having a circle equivalent diameter of 0.4 μm or more and 50 μm or less is 1.5 or less. ing. That is, in the voids having a circle-equivalent diameter of 0.4 μm or more and 50 μm or less in the fluorescent plate, the variation in the circle-equivalent diameter is relatively small, and the fluorescent plate has voids of the same size. As a result, the variation in the reflection of light in the fluorescent phase in the void becomes small, so that the reflectance due to the void can be increased as compared with the case where the diameter corresponding to the circle of the void has a large variation. Therefore, in the fluorescent plate, the light extraction efficiency can be improved.
　（２）上記形態の蛍光板において、円相当径が０．４μｍ以上５０μｍ以下となる空隙のうち、円相当径が１μｍ以上１０μｍ未満となる空隙の個数の割合は、９０％以上であってもよい。この構成によれば、蛍光板において、円相当径が０．４μｍ以上５０μｍ以下となる空隙のうち、円相当径が１μｍ以上１０μｍ未満となる空隙は、個数の割合で９０％以上となっている。これにより、空隙における蛍光相での光の反射のばらつきがさらに小さくなるため、空隙による反射率をさらに高めることができる。したがって、蛍光板において、光の取り出し効率をさらに向上することができる。 (2) In the fluorescent plate of the above embodiment, the ratio of the number of voids having a circle equivalent diameter of 1 μm or more and less than 10 μm may be 90% or more among the voids having a circle equivalent diameter of 0.4 μm or more and 50 μm or less. .. According to this configuration, among the voids having a circle-equivalent diameter of 0.4 μm or more and 50 μm or less, the voids having a circle-equivalent diameter of 1 μm or more and less than 10 μm are 90% or more in proportion to the number of the voids in the fluorescent plate. As a result, the variation in the reflection of light in the fluorescent phase in the void is further reduced, so that the reflectance due to the void can be further increased. Therefore, in the fluorescent plate, the light extraction efficiency can be further improved.
　（３）上記形態の蛍光板において、前記空隙の断面を含む前記蛍光板の断面において、円相当径が０．４μｍ以上５０μｍ以下となる空隙が占める面積の割合は、３％以上１５％以下であってもよい。この構成によれば、蛍光板において、円相当径が０．４μｍ以上５０μｍ以下となる空隙は、蛍光板の断面における面積の割合が３％以上１５％以下となっている。蛍光板の断面における面積の割合が小さい場合、反射回数が少なくなるため反射率が低下する。また、蛍光板の断面における面積の割合が大きい場合、隣り合う空隙の間の距離が短くなるため、反射が繰り返され光が減衰しやすくなる。上記形態の蛍光板では、これらの弊害が生じることを抑制することで、蛍光板の外部への光の取り出し効率を向上させることができる。 (3) In the fluorescent plate of the above embodiment, the ratio of the area occupied by the void having the equivalent circle diameter of 0.4 μm or more and 50 μm or less in the cross section of the fluorescent plate including the cross section of the void is 3% or more and 15% or less. May be good. According to this configuration, in the fluorescent plate, the area ratio of the area in the cross section of the fluorescent plate is 3% or more and 15% or less in the voids having the equivalent circle diameter of 0.4 μm or more and 50 μm or less. When the ratio of the area in the cross section of the fluorescent plate is small, the number of reflections is small and the reflectance is lowered. Further, when the ratio of the area in the cross section of the fluorescent plate is large, the distance between the adjacent voids becomes short, so that the reflection is repeated and the light is easily attenuated. In the fluorescent plate of the above-mentioned form, it is possible to improve the efficiency of extracting light to the outside of the fluorescent plate by suppressing the occurrence of these adverse effects.
　（４）上記形態の蛍光板は、さらに、前記励起光を透過する透光相を備え、前記空隙の断面を含む前記蛍光板の断面において、前記蛍光板に占める前記蛍光相と前記透光相との合計に対する前記蛍光相の面積比は、９５％以下であってもよい。蛍光板を製造するとき、焼結によって形成される空隙が多くなると、空隙はいびつな形状となるため、円相当径の標準偏差が悪くなりやすい。上述の構成によれば、蛍光板に占める蛍光相と透光相との合計に対する蛍光相の面積比は、９５％以下であるため、焼結が進みやすくなり、空隙が形成されにくくなる。これにより、空隙がいびつな形状になりにくいため、円相当径の標準偏差の悪化を抑制することができる。したがって、蛍光板の外部への光の取り出し効率の低下を抑制することができる。 (4) The fluorescent plate of the above embodiment further includes a translucent phase that transmits the excitation light, and is the sum of the fluorescent phase and the translucent phase that occupy the fluorescent plate in the cross section of the fluorescent plate including the cross section of the void. The area ratio of the fluorescent phase to the light of the fluorescent phase may be 95% or less. When manufacturing a fluorescent plate, if the number of voids formed by sintering increases, the voids have a distorted shape, so that the standard deviation of the equivalent circle diameter tends to deteriorate. According to the above configuration, since the area ratio of the fluorescent phase to the total of the fluorescent phase and the translucent phase in the fluorescent plate is 95% or less, sintering easily proceeds and voids are less likely to be formed. As a result, the voids are less likely to have a distorted shape, so that deterioration of the standard deviation of the equivalent circle diameter can be suppressed. Therefore, it is possible to suppress a decrease in the efficiency of extracting light to the outside of the fluorescent screen.
　（５）本発明の別の形態によれば、波長変換部材が提供される。この波長変換部材は、上述の蛍光板と、前記蛍光板に配置され、前記励起光と前記蛍光を反射する反射部材と、を備える。この構成によれば、波長変換部材は、蛍光板から放射される蛍光と励起光とを反射する反射部材を備えている。これにより、蛍光板において光を照射すべき所定の方向とは異なる方向に放射される光は、反射板によって所定の方向に反射されるため、波長変換部材から放射される光量を増加することができる。 (5) According to another embodiment of the present invention, a wavelength conversion member is provided. The wavelength conversion member includes the above-mentioned fluorescent plate and a reflective member arranged on the fluorescent plate and reflecting the excitation light and the fluorescence. According to this configuration, the wavelength conversion member includes a reflection member that reflects the fluorescence emitted from the fluorescent plate and the excitation light. As a result, the light emitted from the fluorescent plate in a direction different from the predetermined direction to be irradiated with the light is reflected by the reflector in the predetermined direction, so that the amount of light emitted from the wavelength conversion member can be increased. ..
　（６）上記形態の波長変換部材は、さらに、前記蛍光板の熱を外部に放出する放熱部材を備えてもよい。この構成によれば、波長変換部材は、蛍光板の熱を外部に放出する放熱部材を備える。これにより、蛍光板において、励起光によって蛍光を発するときに発生する熱を効率的に外部に放出することができるため、蛍光板の温度上昇による消光を抑制することができる。したがって、波長変換部材から放射される光量の低減を抑制することができる。 (6) The wavelength conversion member of the above-described embodiment may further include a heat-dissipating member that releases the heat of the fluorescent plate to the outside. According to this configuration, the wavelength conversion member includes a heat radiating member that releases the heat of the fluorescent plate to the outside. As a result, in the fluorescent plate, the heat generated when the fluorescence is emitted by the excitation light can be efficiently released to the outside, so that quenching due to the temperature rise of the fluorescent plate can be suppressed. Therefore, it is possible to suppress a reduction in the amount of light emitted from the wavelength conversion member.
　（７）本発明のさらに別の形態によれば、光源装置が提供される。この光源装置は、上述の波長変換部材と、前記蛍光板に前記励起光を照射する光源と、を備えてもよい。この構成によれば、光源装置は、蛍光板に励起光を照射する光源を備えている。光源が蛍光板に励起光を照射すると、蛍光板では、励起光によって蛍光が発せられる。発せられた蛍光を含む光は、空隙において比較的多く露出している蛍光相で反射されるため、蛍光板の外部に放射される光量が増加する。これにより、光源装置の発光強度を向上することができる。 (7) According to still another embodiment of the present invention, a light source device is provided. This light source device may include the above-mentioned wavelength conversion member and a light source for irradiating the fluorescent plate with the excitation light. According to this configuration, the light source device includes a light source that irradiates the fluorescent plate with excitation light. When the light source irradiates the fluorescent plate with the excitation light, the fluorescent plate emits fluorescence by the excitation light. Since the emitted light including fluorescence is reflected by the fluorescent phase exposed in a relatively large amount in the void, the amount of light emitted to the outside of the fluorescent plate increases. Thereby, the light emission intensity of the light source device can be improved.
　なお、本発明は、種々の態様で実現することが可能であり、例えば、蛍光板の製造方法、波長変換部材の製造方法、光源装置の製造方法、光源装置を含むシステム、光源装置の制御方法、光源装置を製造装置に製造させるためのコンピュータプログラム等の形態で実現することができる。 The present invention can be realized in various aspects, for example, a method for manufacturing a fluorescent screen, a method for manufacturing a wavelength conversion member, a method for manufacturing a light source device, a system including a light source device, a method for controlling a light source device, and the like. It can be realized in the form of a computer program or the like for causing the manufacturing device to manufacture the light source device.
第１実施形態の蛍光板を備える光源装置の模式図である。It is a schematic diagram of the light source apparatus provided with the fluorescent plate of 1st Embodiment. 蛍光板の拡大断面図である。It is an enlarged sectional view of a fluorescent plate. 第１実施形態の蛍光板の評価試験の第１の結果を示す図である。It is a figure which shows the 1st result of the evaluation test of the fluorescent plate of 1st Embodiment. 第１実施形態の蛍光板の評価試験の第２の結果を示す図である。It is a figure which shows the 2nd result of the evaluation test of the fluorescent plate of 1st Embodiment. 第１実施形態の蛍光板の評価試験の第３の結果を示す図である。It is a figure which shows the 3rd result of the evaluation test of the fluorescent plate of 1st Embodiment.
＜第１実施形態＞
　図１は、第１実施形態の蛍光板１を備える光源装置３の模式図である。本実施形態の蛍光板１は、光源装置３が備える発光ダイオード（ＬＥＤ：Ｌｉｇｈｔ　Ｅｍｉｔｔｉｎｇ　Ｄｉｏｄｅ）や半導体レーザー（ＬＤ：Ｌａｓｅｒ　Ｄｉｏｄｅ）などの光源９が発する光Ｌ１が照射されると、光Ｌ１とは異なる波長の光を蛍光として発する。蛍光板１が発する蛍光は、蛍光板１での蛍光の発生に寄与しなかった光とともに、光Ｌ２として、所定の方向に放射される。本実施形態の光源装置３は、図１に示すように、反射型の光源装置であって、ヘッドランプ、照明、プロジェクタなどの各種光学機器において使用される。光源装置３は、上述の光源９と、波長変換部材２と、を備える。波長変換部材２は、蛍光板１と、反射部材６と、放熱部材７と、接合層８と、を備える。なお、説明の便宜上、図１における各部材のそれぞれの大きさの関係は、実際の関係とは異なるように図示されている。 <First Embodiment>
FIG. 1 is a schematic view of a light source device 3 including the fluorescent screen 1 of the first embodiment. The fluorescent plate 1 of the present embodiment is different from the light L1 when it is irradiated with the light L1 emitted by the light source 9 such as a light emitting diode (LED: Light Emitting Diode) or a semiconductor laser (LD: Laser Diode) included in the light source device 3. It emits light of a wavelength as fluorescence. The fluorescence emitted by the fluorescence plate 1 is radiated in a predetermined direction as light L2 together with the light that did not contribute to the generation of fluorescence in the fluorescence plate 1. As shown in FIG. 1, the light source device 3 of the present embodiment is a reflection type light source device and is used in various optical devices such as head lamps, lighting, and projectors. The light source device 3 includes the above-mentioned light source 9 and a wavelength conversion member 2. The wavelength conversion member 2 includes a fluorescent plate 1, a reflection member 6, a heat dissipation member 7, and a bonding layer 8. For convenience of explanation, the relationship between the sizes of the members in FIG. 1 is shown so as to be different from the actual relationship.
　蛍光板１は、セラミック焼結体から形成されている平板部材である。蛍光板１には、光Ｌ１が入射する入射面１ａと、入射面１ａの反対側に位置する裏面１ｂとが形成されている。蛍光板１は、入射面１ａから入射する光Ｌ１を励起光として、蛍光を発する。蛍光板１は、蛍光を発するときに発熱する。蛍光板１の詳細な構成は、後述する。 The fluorescent plate 1 is a flat plate member formed of a ceramic sintered body. The fluorescent plate 1 is formed with an incident surface 1a on which the light L1 is incident and a back surface 1b located on the opposite side of the incident surface 1a. The fluorescent plate 1 emits fluorescence by using the light L1 incident from the incident surface 1a as excitation light. The fluorescent plate 1 generates heat when it emits fluorescence. The detailed configuration of the fluorescent plate 1 will be described later.
　反射部材６は、銀（Ａｇ）を主成分とする薄膜であって、蛍光板１の裏面１ｂに形成されている。反射部材６は、光源９が発する光Ｌ１のうち蛍光板１を透過した光と、蛍光板１が発した蛍光のうち裏面１ｂの方向に向かう蛍光と、を入射面１ａの方向に反射する。なお、反射部材６は、銀合金やアルミニウム（Ａｌ）など反射率が高い材料から形成されていてもよい。 The reflective member 6 is a thin film containing silver (Ag) as a main component, and is formed on the back surface 1b of the fluorescent plate 1. The reflecting member 6 reflects the light transmitted through the fluorescent screen 1 among the light L1 emitted by the light source 9 and the fluorescence toward the back surface 1b of the fluorescence emitted by the fluorescent plate 1 in the direction of the incident surface 1a. The reflective member 6 may be made of a material having a high reflectance such as a silver alloy or aluminum (Al).
　放熱部材７は、例えば、銅、銅モリブデン合金、銅タングステン合金、アルミニウム、窒化アルミニウムなど、蛍光板１よりも高い熱伝導性を有する材料から形成されている平板部材である。放熱部材７は、接合層８を通して伝わる蛍光板１の熱を外部に放熱する。なお、放熱部材７は、上述した材料からなる単層構造の部材であってもよいし、同種または異なる材料から形成されている多層構造の部材であってもよい。また、放熱部材７の蛍光板１側の面７ａには接合層８との密着性を高める金属膜が配置されていてもよい。 The heat radiating member 7 is a flat plate member made of a material having higher thermal conductivity than the fluorescent plate 1, such as copper, copper molybdenum alloy, copper tungsten alloy, aluminum, and aluminum nitride. The heat radiating member 7 radiates the heat of the fluorescent plate 1 transmitted through the bonding layer 8 to the outside. The heat radiating member 7 may be a single-layered member made of the above-mentioned material, or may be a multi-layered member made of the same or different materials. Further, a metal film that enhances the adhesion to the bonding layer 8 may be arranged on the surface 7a of the heat radiating member 7 on the fluorescent plate 1 side.
　接合層８は、反射部材６と放熱部材７との間に配置され、金（Ａｕ）と錫（Ｓｎ）から形成されている。接合層８は、蛍光板１と放熱部材７とを接合するとともに、蛍光板１で発生する熱を放熱部材７に伝える。なお、接合層８は、金と錫から形成されるほかに、他の材料から形成される半田であってもよいし、銀や銅（Ｃｕ）などの微細粉末を焼結したものであってもよい。 The bonding layer 8 is arranged between the reflecting member 6 and the heat radiating member 7, and is formed of gold (Au) and tin (Sn). The bonding layer 8 joins the fluorescent plate 1 and the heat radiating member 7, and transfers the heat generated by the fluorescent plate 1 to the heat radiating member 7. The bonding layer 8 may be solder formed from other materials in addition to being formed from gold and tin, or may be obtained by sintering fine powder such as silver or copper (Cu). May be good.
　図２は、蛍光板１の拡大断面図である。次に、本実施形態の蛍光板１の特徴について説明する。蛍光板１は、図２に示すように、蛍光相１０と、透光相２０と、空隙３０と、を有する。 FIG. 2 is an enlarged cross-sectional view of the fluorescent plate 1. Next, the features of the fluorescent screen 1 of the present embodiment will be described. As shown in FIG. 2, the fluorescent plate 1 has a fluorescent phase 10, a translucent phase 20, and a void 30.
　蛍光相１０は、複数の蛍光性結晶粒子から構成されている。本実施形態では、この蛍光性結晶粒子は、化学式Ａ３Ｂ５Ｏ１２：Ｃｅで表される組成（いわゆる、ガーネット構造）を有している。ここで、「Ａ３Ｂ５Ｏ１２：Ｃｅ」とは、Ａ３Ｂ５Ｏ１２の中にＣｅが固溶し、元素Ａの一部がＣｅに置換されていることを示す。化学式Ａ３Ｂ５Ｏ１２：Ｃｅ中の元素Ａおよび元素Ｂは、それぞれ下記の元素群から選択される少なくとも１種類の元素から構成されている。
　元素Ａ：Ｓｃ、Ｙ、Ｃｅを除くランタノイド（ただし、元素ＡとしてさらにＧｄを含んでいてもよい）
　元素Ｂ：Ａｌ（ただし、元素ＢとしてさらにＧａを含んでいてもよい）
　なお、蛍光相１０を構成する蛍光性結晶粒子の組成および元素の種類は、上述の組成および元素の種類に限定されず、１つの蛍光相１０が複数種の蛍光性結晶粒子から構成されていてもよい。 The fluorescent phase 10 is composed of a plurality of fluorescent crystal particles. In the present embodiment, the fluorescent crystal particles have a composition represented by the chemical formula A 3 B 5 O 12 : Ce (so-called garnet structure). Here, "A 3 B 5 O 12 : Ce" means that Ce is dissolved in A 3 B 5 O 12 and a part of the element A is replaced with Ce. Chemical formula A 3 B 5 O 12 : Element A and element B in Ce are each composed of at least one element selected from the following element groups.
Element A: Lanthanoids excluding Sc, Y, Ce (however, Gd may be further contained as element A).
Element B: Al (However, Ga may be further contained as element B)
The composition and element types of the fluorescent crystal particles constituting the fluorescent phase 10 are not limited to the above-mentioned composition and element types, and one fluorescent phase 10 is composed of a plurality of types of fluorescent crystal particles. May be good.
　透光相２０は、複数の透光性結晶粒子から構成されている。この透光性結晶粒子は、化学式Ａｌ２Ｏ３で表される組成を有する。透光相２０は、蛍光板１の内部において光を透過するとともに、蛍光相１０が蛍光を発するときに発生する熱を放熱部材７に効率的に伝える伝熱経路にもなる。透光相２０の屈折率は、蛍光相１０の屈折率より小さい。 The translucent phase 20 is composed of a plurality of translucent crystal particles. The translucent crystal particles have a composition represented by the chemical formula Al 2 O 3. The translucent phase 20 transmits light inside the fluorescent plate 1 and also serves as a heat transfer path for efficiently transmitting the heat generated when the fluorescent phase 10 emits fluorescence to the heat radiating member 7. The refractive index of the translucent phase 20 is smaller than that of the fluorescent phase 10.
　空隙３０は、蛍光相１０と透光相２０とに囲まれて形成される。蛍光板１は、図２に示すように、複数の空隙３０を備えている。本実施形態では、空隙３０の断面を含む蛍光板１の断面において、円相当径が０．４μｍ以上５０μｍ以下となる空隙３０の円相当径の標準偏差は、１．５以下となっている。また、円相当径が０．４μｍ以上５０μｍ以下となる空隙３０のうち、円相当径が１μｍ以上１０μｍ未満となる空隙３０の個数の割合は、９０％以上となっている。このことは、蛍光板１が備える複数の空隙３０は、円相当径のばらつきが小さいことを示している。これは、後述する蛍光板１の製造方法において、原料となる造孔材の粒径が揃えられていることと、造孔材が原料内で十分に分散されていることに起因する。本実施形態では、空隙３０の円相当径の平均は、１μｍから１０μｍまでの間となっており、円相当径の平均がこの範囲にあると、空隙による可視光の反射率を高めるにはより好ましい。空隙３０の屈折率は、透光相２０の屈折率より小さい。すなわち、空隙３０の屈折率は、蛍光相１０の屈折率より小さい。 The void 30 is formed by being surrounded by the fluorescent phase 10 and the translucent phase 20. As shown in FIG. 2, the fluorescent plate 1 includes a plurality of voids 30. In the present embodiment, in the cross section of the fluorescent screen 1 including the cross section of the void 30, the standard deviation of the equivalent circle diameter of the void 30 having the equivalent circle diameter of 0.4 μm or more and 50 μm or less is 1.5 or less. Further, among the voids 30 having a circle equivalent diameter of 0.4 μm or more and 50 μm or less, the ratio of the number of voids 30 having a circle equivalent diameter of 1 μm or more and less than 10 μm is 90% or more. This indicates that the plurality of voids 30 included in the fluorescent plate 1 have a small variation in the diameter corresponding to the circle. This is due to the fact that the particle size of the pore-forming material as a raw material is uniform and that the pore-forming material is sufficiently dispersed in the raw material in the method for producing the fluorescent plate 1 described later. In the present embodiment, the average circle-equivalent diameter of the void 30 is between 1 μm and 10 μm, and when the average circle-equivalent diameter is in this range, it is more necessary to increase the reflectance of visible light by the void. preferable. The refractive index of the void 30 is smaller than that of the translucent phase 20. That is, the refractive index of the void 30 is smaller than the refractive index of the fluorescent phase 10.
　さらに、本実施形態では、図２に示すような空隙３０の断面を含む蛍光板１の断面において、円相当径が０．４μｍ以上５０μｍ以下となる空隙３０が占める面積の割合は、３％以上１５％以下となっている。言い換えれば、蛍光板１では、円相当径が０．４μｍ以上５０μｍ以下となる空隙３０は、体積比において、３％以上１５％以下で蛍光板１の内部に存在しているともいえる。また、本実施形態では、空隙３０の断面を含む蛍光板１の断面において、蛍光板１に占める蛍光相１０と透光相２０との合計に対する蛍光相１０の面積比は、６０％となっている。言い換えれば、蛍光板１における空隙３０を除いた部分は、体積比において、６０％の蛍光相１０と、４０％の透光相２０とによって構成されている。蛍光相１０の面積比は、焼結が進みやすくなり、空隙が形成されにくくなるように、９５％以下であることが望ましい。 Further, in the present embodiment, in the cross section of the fluorescent screen 1 including the cross section of the void 30 as shown in FIG. 2, the ratio of the area occupied by the void 30 having the equivalent circle diameter of 0.4 μm or more and 50 μm or less is 3% or more and 15 It is less than%. In other words, in the fluorescent plate 1, it can be said that the voids 30 having a circle equivalent diameter of 0.4 μm or more and 50 μm or less exist inside the fluorescent plate 1 at a volume ratio of 3% or more and 15% or less. Further, in the present embodiment, in the cross section of the fluorescent plate 1 including the cross section of the void 30, the area ratio of the fluorescent phase 10 to the total of the fluorescent phase 10 and the translucent phase 20 in the fluorescent plate 1 is 60%. In other words, the portion of the fluorescent plate 1 excluding the void 30 is composed of a fluorescent phase 10 having a volume ratio of 60% and a translucent phase 20 having a volume ratio of 40%. The area ratio of the fluorescent phase 10 is preferably 95% or less so that sintering can easily proceed and voids are less likely to be formed.
　次に、蛍光板１の製造方法について説明する。蛍光板１の製造方法では、最初に、秤量したＡｌ２Ｏ３と、Ｙ２Ｏ３と、ＣｅＯ２とを、純水とともにボールミル中に投入し、粉砕混合を１６時間行った。この粉砕混合によって得られたスラリーを乾燥し、乾燥したスラリーを用いてスプレードライヤーで造粒を行った。次に、造粒された粒子に、所定量の造孔材と、所定量のバインダーとを混合し、スクリュー式の混錬機を用いて高いせん断力を加えながら混練を行い、坏土を作製した。高いせん断力を加えながら混練することにより、造孔材が均一に分散し凝集しにくくなるため、造孔材の凝集による円相当径の標準偏差を低くすることができる。作製した坏土を押出成形機を用いてシート形状に成形し、大気雰囲気中において１７００℃で焼成し、焼結させることで、蛍光板１が製造される。 Next, a method for manufacturing the fluorescent plate 1 will be described. In the method for producing the fluorescent plate 1, first, weighed Al 2 O 3 , Y 2 O 3 , and CeO 2 were put into a ball mill together with pure water, and pulverized and mixed for 16 hours. The slurry obtained by this pulverization and mixing was dried, and the dried slurry was used for granulation with a spray dryer. Next, a predetermined amount of pore-forming material and a predetermined amount of binder are mixed with the granulated particles, and kneading is performed using a screw-type kneader while applying a high shearing force to prepare clay. did. By kneading while applying a high shearing force, the pore-forming material is uniformly dispersed and difficult to aggregate, so that the standard deviation of the equivalent circle diameter due to the aggregation of the pore-forming material can be reduced. The fluorescent plate 1 is manufactured by molding the produced clay into a sheet shape using an extrusion molding machine, firing at 1700 ° C. in an air atmosphere, and sintering the soil.
　さらに、蛍光板１を備える波長変換部材２を製造する場合、蛍光板１の裏面１ｂに銀を蒸着またはスパッタリングし、反射部材６を製膜する。次に、蛍光板１に成膜された反射部材６と放熱部材７との間に、金錫半田箔を挟みこんだ状態で、窒素雰囲気中または水素雰囲気中のリフロー炉において加熱する。これにより、蛍光板１と放熱部材７とが接合され、波長変換部材２が製造される。なお、金錫半田箔を使用する代わりに、金錫半田ペーストを塗布して蛍光板１と放熱部材７とを接合してもよい。 Further, when the wavelength conversion member 2 including the fluorescent plate 1 is manufactured, silver is vapor-deposited or sputtered on the back surface 1b of the fluorescent plate 1 to form a film of the reflective member 6. Next, the gold-tin solder foil is sandwiched between the reflective member 6 and the heat-dissipating member 7 formed on the fluorescent plate 1 and heated in a reflow oven in a nitrogen atmosphere or a hydrogen atmosphere. As a result, the fluorescent plate 1 and the heat radiating member 7 are joined to each other, and the wavelength conversion member 2 is manufactured. Instead of using the gold-tin solder foil, the gold-tin solder paste may be applied to bond the fluorescent plate 1 and the heat radiating member 7.
　さらに、波長変換部材２を備える光源装置３を製造する場合、波長変換部材２が備える蛍光板１の入射面１ａに光が照射されるように、光源９をセットし、波長変換部材２と光源９とをパッケージする。これにより、光源装置３が製造される。 Further, in the case of manufacturing the light source device 3 including the wavelength conversion member 2, the light source 9 is set so that the incident surface 1a of the fluorescent plate 1 included in the wavelength conversion member 2 is irradiated with light, and the wavelength conversion member 2 and the light source 9 are provided. And package. As a result, the light source device 3 is manufactured.
　次に、本実施形態の蛍光板１についての評価試験の内容およびその結果を説明する。本評価試験では、複数の蛍光板のサンプルを作製し、それぞれのサンプルに光を照射したときのサンプルの輝度を測定することで、そのサンプルの光の取り出し効率を評価した。本評価試験では、（ｉ）空隙の円相当径の標準偏差、（ｉｉ）空隙の円相当径、（ｉｉｉ）蛍光板の断面における空隙の面積比の３つの項目に着目して評価試験を行った。 Next, the contents of the evaluation test for the fluorescent plate 1 of the present embodiment and the results thereof will be described. In this evaluation test, samples of a plurality of fluorescent plates were prepared, and the brightness of the sample when each sample was irradiated with light was measured to evaluate the light extraction efficiency of the sample. In this evaluation test, the evaluation test was conducted focusing on three items: (i) standard deviation of the circle-equivalent diameter of the void, (ii) the circle-equivalent diameter of the void, and (iii) the area ratio of the void in the cross section of the fluorescent plate. ..
　本評価試験では、サンプルの特性について、以下の方法を用いて測定を行った。
・空隙の円相当径
　サンプルを切断し、鏡面加工された切断面をＦＥ－ＳＥＭによって観察した。ＷｉｎＲＯＯＦを用いる画像解析では、任意の５か所の点で断面画像を取得し、インターセプト法に用いて空隙の円相当径を測定した。
・分散性
　上述したインターセプト法を用いて、測定した空隙の円相当径の分布（縦軸：頻度、横軸：円相当径）を計算した。このとき、最大頻度を示す円相当径から頻度が全体の５%となる円相当径の差を計算し、分散性とした。
・標準偏差
　上述したインターセプト法を用いて測定した空隙の円相当径から標準偏差を算出した。
・空隙の面積比
　画像処理によって二値化したサンプルの断面画像において、複数の空隙の合計面積と、空隙以外の部分の面積と、を算出し、断面画像全体の面積に対する複数の空隙の合計面積の割合を算出した。
・輝度
　サンプルの厚みが２００μｍとなるように研磨し、表面を鏡面加工することで輝度計測用のサンプルを作製した。この輝度計測用サンプルに、波長４５０ｎｍのレーザ（レーザ径：０．４ｍｍ、レーザ出力：５Ｗ）を照射し、反射方向の光を輝度計にて測定した。 In this evaluation test, the characteristics of the sample were measured using the following method.
-A sample with a diameter equivalent to a circle of voids was cut, and the mirror-finished cut surface was observed by FE-SEM. In the image analysis using WinROOF, cross-sectional images were acquired at arbitrary five points and used in the intercept method to measure the equivalent circle diameter of the void.
Dispersibility Using the intercept method described above, the distribution of the measured circle-equivalent diameter of the void (vertical axis: frequency, horizontal axis: circle-equivalent diameter) was calculated. At this time, the difference between the circle-equivalent diameters indicating the maximum frequency and the circle-equivalent diameter at which the frequency is 5% of the total was calculated and used as the dispersibility.
-Standard deviation The standard deviation was calculated from the equivalent circle diameter of the voids measured using the intercept method described above.
-Area ratio of voids In the cross-sectional image of the sample binarized by image processing, the total area of multiple voids and the area of the part other than the voids are calculated, and the total area of the plurality of voids with respect to the total area of the cross-sectional image. The ratio of was calculated.
-A sample for luminance measurement was prepared by polishing so that the thickness of the luminance sample was 200 μm and mirror-finishing the surface. This luminance measurement sample was irradiated with a laser having a wavelength of 450 nm (laser diameter: 0.4 mm, laser output: 5 W), and the light in the reflection direction was measured with a luminance meter.
　図３は、第１実施形態の蛍光板１の評価試験の第１の結果を示す図である。図４は、第１実施形態の蛍光板１の評価試験の第２の結果を示す図である。図５は、第１実施形態の蛍光板１の評価試験の第３の結果を示す図である。次に、上述した３つの項目のそれぞれについての評価試験の結果を説明する。 FIG. 3 is a diagram showing the first result of the evaluation test of the fluorescent plate 1 of the first embodiment. FIG. 4 is a diagram showing the second result of the evaluation test of the fluorescent plate 1 of the first embodiment. FIG. 5 is a diagram showing the third result of the evaluation test of the fluorescent plate 1 of the first embodiment. Next, the results of the evaluation test for each of the above three items will be described.
（ｉ）空隙の円相当径の標準偏差
　評価試験用のサンプルは、上述した蛍光板１の製造方法に準じた方法において、１つのサンプルにおける蛍光相の割合が、体積比で６０%となるように、Ａｌ２Ｏ３と、Ｙ２Ｏ３と、ＣｅＯ２とを秤量するとともに、造粒された粒子に混合させる造孔材の粒度分布を変化させることによって、サンプル１、サンプル２、および、サンプル４の坏土を作製した。また、サンプル３は、造孔材を加えることなく坏土を作製した。空隙の円相当径の標準偏差についての試験結果を図３に示す。図３の表中に示すサンプル１は、本実施形態の蛍光板１を模擬したサンプルであり、今回の評価試験における基準サンプルとする。図３に示すように、標準偏差が１．５以下の場合、輝度が５００ｃｄ／ｍｍ２以上となることが明らかとなった。一方、空隙がないサンプル３、および、標準偏差が７．４のサンプル４では、輝度が３５０ｃｄ／ｍｍ２以下となることが明らかとなった。 (I) For the sample for the standard deviation evaluation test of the equivalent circle diameter of the void, the ratio of the fluorescent phase in one sample is 60% by volume in the method according to the method for manufacturing the fluorescent plate 1 described above. , Al 2 O 3 , Y 2 O 3 , and CeO 2, and sample 1, sample 2, and sample by changing the particle size distribution of the pore-forming material to be mixed with the granulated particles. 4 particles were prepared. Further, in the sample 3, the clay was prepared without adding the pore-forming material. FIG. 3 shows the test results for the standard deviation of the equivalent circle diameter of the void. The sample 1 shown in the table of FIG. 3 is a sample simulating the fluorescent screen 1 of the present embodiment, and is used as a reference sample in this evaluation test. As shown in FIG. 3, it was clarified that when the standard deviation was 1.5 or less, the brightness was 500 cd / mm 2 or more. On the other hand, it was clarified that the brightness of the sample 3 having no void and the sample 4 having a standard deviation of 7.4 was 350 cd / mm 2 or less.
（ｉｉ）空隙の円相当径、
　評価試験用のサンプルは、上述した蛍光板１の製造方法に準じた方法において、造孔材の粒度分布を変化させることによって、サンプル５～８を作製した。空隙の円相当径についての試験結果を図４に示す。図４の表中に示すサンプル１は、図３にも示した基準サンプルである。図４に示すように、空隙の円相当径が、１．０μｍとなる場合と１０μｍとなる場合、輝度は比較的低い値（１．０μｍ：４５０ｃｄ／ｍｍ２、１０．０μｍ：３６０ｃｄ／ｍｍ２）となることが明らかとなった。一方、空隙の円相当径が、１．０μｍより大きく１０μｍより小さい（３．５μｍ、４．２μｍ、５、４μｍ）場合、輝度は、６００ｃｄ／ｍｍ２以上となり、比較的高い値となることが明らかとなった。 (Ii) Circular equivalent diameter of the void,
As the sample for the evaluation test, Samples 5 to 8 were prepared by changing the particle size distribution of the pore-forming material by the method according to the above-mentioned manufacturing method of the fluorescent plate 1. The test results for the equivalent circle diameter of the void are shown in FIG. Sample 1 shown in the table of FIG. 4 is a reference sample also shown in FIG. As shown in FIG. 4, when the equivalent circle diameter of the void is 1.0 μm and 10 μm, the brightness is a relatively low value (1.0 μm: 450 cd / mm 2 , 10.0 μm: 360 cd / mm 2). ). On the other hand, when the equivalent circle diameter of the void is larger than 1.0 μm and smaller than 10 μm (3.5 μm, 4.2 μm, 5, 4 μm), the brightness is 600 cd / mm 2 or more, which may be a relatively high value. It became clear.
（ｉｉｉ）蛍光板の断面における空隙の面積比
　評価試験用のサンプルは、上述した蛍光板１の製造方法に準じた方法において、造孔材の添加量を変化させることによって、サンプル９～１２を作製した。蛍光板の断面における空隙の面積比についての試験結果を図５に示す。図５の表中に示すサンプル１は、図３にも示した基準サンプルである。図５に示すように、空隙の面積比が、１％となる場合と３０％となる場合、輝度は、比較的低い値（１％：３３０ｃｄ／ｍｍ２、３０％：２８０ｃｄ／ｍｍ２）となることが明らかとなった。一方、空隙の面積比が、３％以上１５％以下（３％、８％、１５％）場合、輝度は、６７０ｃｄ／ｍｍ２以上となり、比較的高い値となることが明らかとなった。 (Iii) As the sample for the area ratio evaluation test of the void in the cross section of the fluorescent plate, samples 9 to 12 were prepared by changing the addition amount of the pore-forming material by the method according to the above-mentioned manufacturing method of the fluorescent plate 1. .. FIG. 5 shows the test results regarding the area ratio of the voids in the cross section of the fluorescent screen. Sample 1 shown in the table of FIG. 5 is a reference sample also shown in FIG. As shown in FIG. 5, when the area ratio of the voids is 1% and 30%, the brightness is a relatively low value (1%: 330cd / mm 2 , 30%: 280cd / mm 2 ). It became clear that it would be. On the other hand, when the area ratio of the voids was 3% or more and 15% or less (3%, 8%, 15%), the brightness was 670 cd / mm 2 or more, which was a relatively high value.
　以上説明した、本実施形態の蛍光板１によれば、蛍光板１が備える空隙３０は、空隙３０の断面を含む蛍光板１の断面において、円相当径が０．４μｍ以上５０μｍ以下となる空隙３０の円相当径の標準偏差が、１．５以下となっている。すなわち、蛍光板１において円相当径が０．４μｍ以上５０μｍ以下となる空隙３０は、円相当径のばらつきが比較的小さくなっており、蛍光板１には、同じような大きさの空隙３０があることとなる。これにより、空隙３０における蛍光相１０での光の反射のばらつきが小さくなるため、空隙３０の円相当径に大きなばらつきがある場合に比べ、空隙３０による反射率を高めることができる。したがって、蛍光板１において、光の取り出し効率を向上することができる。 According to the fluorescent plate 1 of the present embodiment described above, the void 30 included in the fluorescent plate 1 is a circle of voids 30 having a circle equivalent diameter of 0.4 μm or more and 50 μm or less in the cross section of the fluorescent plate 1 including the cross section of the void 30. The standard deviation of the equivalent diameter is 1.5 or less. That is, the void 30 having the equivalent circle diameter of 0.4 μm or more and 50 μm or less in the fluorescent plate 1 has a relatively small variation in the equivalent circle diameter, and the fluorescent plate 1 has the void 30 having the same size. It becomes. As a result, the variation in the reflection of light in the fluorescent phase 10 in the void 30 becomes small, so that the reflectance due to the void 30 can be increased as compared with the case where the diameter corresponding to the circle of the void 30 has a large variation. Therefore, in the fluorescent plate 1, the light extraction efficiency can be improved.
　また、本実施形態の蛍光板１によれば、蛍光板１において、円相当径が０．４μｍ以上５０μｍ以下となる空隙３０のうち、円相当径が１μｍ以上１０μｍ未満となる空隙３０は、個数の割合で９０％以上となっている。これにより、空隙３０における蛍光相１０での光の反射のばらつきがさらに小さくなるため、空隙３０による反射率をさらに高めることができる。したがって、蛍光板１において、光の取り出し効率をさらに向上することができる。 Further, according to the fluorescent plate 1 of the present embodiment, among the voids 30 having a circular equivalent diameter of 0.4 μm or more and 50 μm or less, the voids 30 having a circular equivalent diameter of 1 μm or more and less than 10 μm are the ratio of the number. It is 90% or more. As a result, the variation in the reflection of light in the fluorescent phase 10 in the void 30 is further reduced, so that the reflectance due to the void 30 can be further increased. Therefore, in the fluorescent plate 1, the light extraction efficiency can be further improved.
　また、本実施形態の蛍光板１によれば、蛍光板１において、円相当径が０．４μｍ以上５０μｍ以下となる空隙３０は、蛍光板１の断面における面積の割合が３％以上１５％以下となっている。蛍光板の断面における面積の割合が小さい場合、反射回数が少なくなるため反射率が低下する。また、蛍光板の断面における面積の割合が大きい場合、隣り合う空隙の間の距離が短くなるため、反射が繰り返され光が減衰しやすくなる。本実施形態の蛍光板１では、これらの弊害が生じることを抑制することで、蛍光板１の外部への光の取り出し効率を向上させることができる。 Further, according to the fluorescent plate 1 of the present embodiment, in the fluorescent plate 1, the air gap 30 having a circle equivalent diameter of 0.4 μm or more and 50 μm or less has an area ratio of 3% or more and 15% or less in the cross section of the fluorescent plate 1. There is. When the ratio of the area in the cross section of the fluorescent plate is small, the number of reflections is small and the reflectance is lowered. Further, when the ratio of the area in the cross section of the fluorescent plate is large, the distance between the adjacent voids becomes short, so that the reflection is repeated and the light is easily attenuated. In the fluorescent plate 1 of the present embodiment, the efficiency of extracting light to the outside of the fluorescent plate 1 can be improved by suppressing the occurrence of these adverse effects.
　また、蛍光板を製造するとき、焼結によって形成される空隙が多くなると、空隙はいびつな形状となるため、円相当径の標準偏差が悪くなりやすい。本実施形態の蛍光板１によれば、空隙３０の断面を含む蛍光板１の断面において、蛍光板１に占める蛍光相１０と透光相２０との合計に対する蛍光相１０の面積比は、６０％になっている。これにより、本実施形態の蛍光板１では、焼結が進みやすくなり、空隙が形成されにくくなるため、空隙がいびつな形状になりにくく、円相当径の標準偏差の悪化を抑制することができる。したがって、蛍光板１の外部への光の取り出し効率の低下を抑制することができる。 Further, when manufacturing a fluorescent plate, if the number of voids formed by sintering increases, the voids have a distorted shape, so that the standard deviation of the equivalent circle diameter tends to deteriorate. According to the fluorescent plate 1 of the present embodiment, in the cross section of the fluorescent plate 1 including the cross section of the void 30, the area ratio of the fluorescent phase 10 to the total of the fluorescent phase 10 and the translucent phase 20 in the fluorescent plate 1 is 60%. ing. As a result, in the fluorescent plate 1 of the present embodiment, sintering is facilitated and voids are less likely to be formed, so that the voids are less likely to have a distorted shape, and deterioration of the standard deviation of the equivalent circle diameter can be suppressed. Therefore, it is possible to suppress a decrease in the efficiency of extracting light to the outside of the fluorescent plate 1.
　また、本実施形態の波長変換部材２によれば、波長変換部材２は、蛍光板１から放射される蛍光と励起光とを反射する反射部材６を備えている。これにより、例えば、図１に示すように、蛍光板１において光Ｌ２が放射される方向とは異なる方向に放射される光は、反射部材６によって所定の方向に反射されるため、波長変換部材２から放射される光量を増加することができる。 Further, according to the wavelength conversion member 2 of the present embodiment, the wavelength conversion member 2 includes a reflection member 6 that reflects the fluorescence emitted from the fluorescent plate 1 and the excitation light. As a result, for example, as shown in FIG. 1, the light emitted in the direction different from the direction in which the light L2 is emitted in the fluorescent plate 1 is reflected by the reflecting member 6 in a predetermined direction, so that the wavelength conversion member 2 The amount of light emitted from can be increased.
　また、本実施形態の波長変換部材２によれば、波長変換部材２は、蛍光板１の熱を外部に放出する放熱部材７を備える。これにより、蛍光板１において、励起光によって蛍光を発するときに発生する熱を効率的に外部に放出することができるため、蛍光板１の温度上昇による消光を抑制することができる。したがって、波長変換部材２から放射される光量の低減を抑制することができる。 Further, according to the wavelength conversion member 2 of the present embodiment, the wavelength conversion member 2 includes a heat dissipation member 7 that releases the heat of the fluorescent plate 1 to the outside. As a result, in the fluorescent plate 1, the heat generated when the fluorescence is emitted by the excitation light can be efficiently released to the outside, so that quenching due to the temperature rise of the fluorescent plate 1 can be suppressed. Therefore, it is possible to suppress a reduction in the amount of light emitted from the wavelength conversion member 2.
　また、本実施形態の光源装置３によれば、光源装置３は、蛍光板１に光Ｌ１を照射する光源９を備えている。光源９が蛍光板１に光Ｌ１を照射すると、蛍光板１は、光Ｌ１の一部の光によって蛍光を発する。蛍光板１が発する蛍光は、空隙３０において比較的多く露出している蛍光相１０で反射されるため、蛍光板１の外部に放射される光量が増加する。これにより、光源装置３の発光強度を向上することができる。 Further, according to the light source device 3 of the present embodiment, the light source device 3 includes a light source 9 that irradiates the fluorescent plate 1 with the light L1. When the light source 9 irradiates the fluorescent plate 1 with the light L1, the fluorescent plate 1 emits fluorescence by a part of the light of the light L1. Since the fluorescence emitted by the fluorescent plate 1 is reflected by the fluorescent phase 10 exposed in a relatively large amount in the void 30, the amount of light radiated to the outside of the fluorescent plate 1 increases. Thereby, the light emission intensity of the light source device 3 can be improved.
＜本実施形態の変形例＞
　本発明は上記の実施形態に限られるものではなく、その要旨を逸脱しない範囲において種々の態様において実施することが可能であり、例えば次のような変形も可能である。 <Modified example of this embodiment>
The present invention is not limited to the above embodiment, and can be carried out in various embodiments without departing from the gist thereof, and for example, the following modifications are also possible.
　［変形例１］
　上述の実施形態では、円相当径が０．４μｍ以上５０μｍ以下となる空隙３０のうち、９０％以上の空隙３０の円相当径は、１μｍ以上１０μｍ未満であるとした。しかしながら、円相当径が１μｍ以上１０μｍ未満となる空隙３０の割合が、これに限定されない。９０％未満であってもよく、円相当径が０．４μｍ以上５０μｍ以下となる空隙の円相当径の標準偏差は、１．５以下であればよい。 [Modification 1]
In the above-described embodiment, among the voids 30 having a circle-equivalent diameter of 0.4 μm or more and 50 μm or less, 90% or more of the voids 30 have a circle-equivalent diameter of 1 μm or more and less than 10 μm. However, the ratio of the voids 30 having a circle-equivalent diameter of 1 μm or more and less than 10 μm is not limited to this. It may be less than 90%, and the standard deviation of the circle-equivalent diameter of the void having a circle-equivalent diameter of 0.4 μm or more and 50 μm or less may be 1.5 or less.
　［変形例２］
　上述の実施形態では、空隙３０の断面を含む蛍光板１の断面において、円相当径が０．４μｍ以上５０μｍ以下となる空隙３０が占める面積の割合は、３％以上１５％以下となっているとした。しかしながら、円相当径が０．４μｍ以上５０μｍ以下となる空隙３０が占める面積の割合はこれに限定されない。３％より小さくても１５％より大きくてもよいが、空隙が少なすぎると空隙での反射による効果は小さいし、空隙が多すぎると反射回数が増えることで光が減衰し反射率が低下するため、３％以上１５％以下が望ましい。 [Modification 2]
In the above embodiment, in the cross section of the fluorescent screen 1 including the cross section of the void 30, the ratio of the area occupied by the void 30 having the equivalent circle diameter of 0.4 μm or more and 50 μm or less is 3% or more and 15% or less. did. However, the ratio of the area occupied by the void 30 having the equivalent circle diameter of 0.4 μm or more and 50 μm or less is not limited to this. It may be smaller than 3% or larger than 15%, but if there are too few voids, the effect of reflection in the voids will be small, and if there are too many voids, the number of reflections will increase and the light will be attenuated and the reflectance will decrease. Therefore, 3% or more and 15% or less are desirable.
　［変形例３］
　上述の実施形態では、空隙３０の断面を含む蛍光板１の断面において、空隙３０の断面を含む蛍光板１の断面において、蛍光板１に占める蛍光相１０と透光相２０との合計に対する蛍光相１０の面積比は、６０％になっているとした。蛍光相１０の面積比が１０％未満または９５％より大きい場合、焼結体自体の焼結性が上がらないため、意図して添加した造孔材による空隙以外に空隙が生成されやすくなる。このような意図しない空隙が多くなると、いびつな形状の空隙ができやすくなるため、空隙の円相当径の標準偏差が悪化するおそれがある。したがって、蛍光相１０の面積比は、蛍光板１の焼結時に、できるだけ意図しない空隙が形成されないように、１０％以上９５％以下であることが望ましい。 [Modification 3]
In the above-described embodiment, in the cross section of the fluorescent plate 1 including the cross section of the void 30, in the cross section of the fluorescent plate 1 including the cross section of the void 30, the fluorescent phase 10 with respect to the total of the fluorescent phase 10 and the translucent phase 20 occupied in the fluorescent plate 1 The area ratio is said to be 60%. When the area ratio of the fluorescent phase 10 is less than 10% or larger than 95%, the sinterability of the sintered body itself does not improve, so that voids other than the voids due to the intentionally added pore-forming material are likely to be generated. When the number of such unintended voids increases, voids having a distorted shape are likely to be formed, so that the standard deviation of the diameter corresponding to the circle of the voids may be deteriorated. Therefore, it is desirable that the area ratio of the fluorescent phase 10 is 10% or more and 95% or less so that unintended voids are not formed as much as possible when the fluorescent plate 1 is sintered.
　［変形例４］
　上述の実施形態では、光源装置３は、反射型の光源装置であるとした。しかしながら、蛍光板１は、透過型の光源装置に適用されてもよい。 [Modification 4]
In the above-described embodiment, the light source device 3 is a reflection type light source device. However, the fluorescent plate 1 may be applied to a transmission type light source device.
　以上、実施形態、変形例に基づき本態様について説明してきたが、上記した態様の実施の形態は、本態様の理解を容易にするためのものであり、本態様を限定するものではない。本態様は、その趣旨並びに特許請求の範囲を逸脱することなく、変更、改良され得るとともに、本態様にはその等価物が含まれる。また、その技術的特徴が本明細書中に必須なものとして説明されていなければ、適宜、削除することができる。 The present embodiment has been described above based on the embodiments and modifications, but the embodiments of the above-described embodiments are for facilitating the understanding of the present embodiments, and are not limited to the present embodiments. This aspect may be modified or improved without departing from its spirit and claims, and this aspect includes its equivalent. Further, if the technical feature is not described as essential in the present specification, it may be deleted as appropriate.
　　１…蛍光板
　　２…波長変換部材
　　３…光源装置
　　６…反射部材
　　７…放熱部材
　　８…接合層
　　９…光源
　　１０…蛍光相
　　２０…透光相
　　３０…空隙 1 ... Fluorescent plate 2 ... Wavelength conversion member 3 ... Light source device 6 ... Reflection member 7 ... Heat dissipation member 8 ... Bonding layer 9 ... Light source 10 ... Fluorescent phase 20 ... Translucent phase 30 ... Air gap

Claims (7)

  1. 　蛍光板であって、
    　励起光によって蛍光を発する蛍光相と、
    　複数の空隙と、を備え、
    　前記空隙の断面を含む前記蛍光板の断面において、円相当径が０．４μｍ以上５０μｍ以下となる空隙の円相当径の標準偏差は、１．５以下である、
    　ことを特徴とする蛍光板。     It ’s a fluorescent plate,
    A fluorescent phase that fluoresces due to excitation light,
    With multiple voids,
    In the cross section of the fluorescent plate including the cross section of the void, the standard deviation of the equivalent circle diameter of the void having the equivalent circle diameter of 0.4 μm or more and 50 μm or less is 1.5 or less.
    A fluorescent plate characterized by that.
  2. 　請求項１に記載の蛍光板であって、
    　円相当径が０．４μｍ以上５０μｍ以下となる空隙のうち、円相当径が１μｍ以上１０μｍ未満となる空隙の個数の割合は、９０％以上である、
    　ことを特徴とする蛍光板。     The fluorescent plate according to claim 1.
    Of the voids having a circle equivalent diameter of 0.4 μm or more and 50 μm or less, the ratio of the number of voids having a circle equivalent diameter of 1 μm or more and less than 10 μm is 90% or more.
    A fluorescent plate characterized by that.
  3. 　請求項１または請求項２に記載の蛍光板であって、
    　前記空隙の断面を含む前記蛍光板の断面において、円相当径が０．４μｍ以上５０μｍ以下となる空隙が占める面積の割合は、３％以上１５％以下である、
    　ことを特徴とする蛍光板。     The fluorescent plate according to claim 1 or 2.
    In the cross section of the fluorescent plate including the cross section of the void, the ratio of the area occupied by the void having the equivalent circle diameter of 0.4 μm or more and 50 μm or less is 3% or more and 15% or less.
    A fluorescent plate characterized by that.
  4. 　請求項１から請求項３のいずれか一項に記載の蛍光板は、さらに、
    　前記励起光を透過する透光相を備え、
    　前記空隙の断面を含む前記蛍光板の断面において、前記蛍光板に占める前記蛍光相と前記透光相との合計に対する前記蛍光相の面積比は、９５％以下である、
    　ことを特徴とする蛍光板。     The fluorescent plate according to any one of claims 1 to 3 further comprises.
    It has a translucent phase that transmits the excitation light.
    In the cross section of the fluorescent plate including the cross section of the void, the area ratio of the fluorescent phase to the total of the fluorescent phase and the translucent phase in the fluorescent plate is 95% or less.
    A fluorescent plate characterized by that.
  5. 　波長変換部材であって、
    　請求項１から請求項４のいずれか一項に記載の蛍光板と、
    　前記蛍光板に配置されて、前記励起光と前記蛍光を反射する反射部材と、を備える、
    　ことを特徴とする波長変換部材。     It is a wavelength conversion member
    The fluorescent plate according to any one of claims 1 to 4,
    A reflecting member arranged on the fluorescent plate and reflecting the excitation light and the fluorescence is provided.
    A wavelength conversion member characterized by this.
  6. 　請求項５に記載の波長変換部材は、さらに、
    　前記蛍光板の熱を外部に放出する放熱部材を備える、
    　ことを特徴とする波長変換部材。     The wavelength conversion member according to claim 5 further comprises.
    A heat radiating member that releases the heat of the fluorescent plate to the outside is provided.
    A wavelength conversion member characterized by this.
  7. 　光源装置であって、
    　請求項５または請求項６に記載の波長変換部材と、
    　前記蛍光板に向けて光を放出する光源と、を備える、
    　光源装置。     It is a light source device
    The wavelength conversion member according to claim 5 or 6,
    A light source that emits light toward the fluorescent plate.
    Light source device.
PCT/JP2021/021146 2020-06-08 2021-06-03 Fluorescent plate, wavelength conversion member, and light source device WO2021251253A1 (en)

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